package com.xs.tool.common.interceptor;

import com.auth0.jwt.JWT;
import com.auth0.jwt.algorithms.Algorithm;
import com.auth0.jwt.exceptions.JWTDecodeException;
import com.auth0.jwt.exceptions.JWTVerificationException;
import com.auth0.jwt.interfaces.JWTVerifier;
import com.xs.tool.common.jwt.JwtToken;
import com.xs.tool.common.jwt.PassToken;
import com.xs.tool.model.User;
import com.xs.tool.service.UserService;
import java.lang.reflect.Method;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

/**
 * 登录拦截器
 */
public class AuthenticationInterceptor implements HandlerInterceptor {
    @Autowired
    UserService userService;
    @Override
    public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object object) throws Exception {
      String token = httpServletRequest.getHeader("token");// 从 http 请求头中取出 token
      // 如果不是映射到方法直接通过
      if(!(object instanceof HandlerMethod)){
        return true;
      }
      HandlerMethod handlerMethod=(HandlerMethod)object;
      Method method=handlerMethod.getMethod();
      //检查是否有passtoken注释，有则跳过认证
      if (method.isAnnotationPresent(PassToken.class)) {
        PassToken passToken = method.getAnnotation(PassToken.class);
        if (passToken.required()) {
          return true;
        }
      }
      //检查有没有需要用户权限的注解
      if (method.isAnnotationPresent(JwtToken.class)) {
        JwtToken jwtToken = method.getAnnotation(JwtToken.class);
        if (jwtToken.required()) {
          // 执行认证
          if (token == null) {
            throw new RuntimeException("无token，请重新登录");
          }
          // 获取 token 中的 user id
          String userId;
          try {
            userId = JWT.decode(token).getAudience().get(0);
          } catch (JWTDecodeException j) {
            throw new RuntimeException("401");
          }
          User user = userService.getOne(userId);
          if (user == null) {
            throw new RuntimeException("用户不存在，请重新登录");
          }
          // 验证 token
          JWTVerifier jwtVerifier = JWT.require(Algorithm.HMAC256(user.getPassword())).build();
          try {
            jwtVerifier.verify(token);
          } catch (JWTVerificationException e) {
            throw new RuntimeException("401");
          }
          return true;
        }
      }
      return true;
    }

    @Override
    public void postHandle(HttpServletRequest httpServletRequest,
        HttpServletResponse httpServletResponse,
        Object o, ModelAndView modelAndView) throws Exception {

    }
    @Override
    public void afterCompletion(HttpServletRequest httpServletRequest,
        HttpServletResponse httpServletResponse,
        Object o, Exception e) throws Exception {
    }
  }
